Urban Seismic Hazards
- The liquefaction hazard map
predicts the approximate percentage of each designated area that will have
surface manifestations of liquefaction during an M7.1 earthquake on the
Hayward fault. An earthquake of this magnitude is expected if the whole
Hayward fault ruptures in a single event (Working Group on California
Earthquake Probabilities, 1999). This event dominates the deaggregated
hazard near the eastern shore of San Francisco Bay.
- The type of soil at
a site affects the intensity of shaking there. Learn about this effect and
use interactive maps to look up the soil type at any site in the San
Francisco Bay Area.
- Shows the distribution of rock and sediment having
different vulnerabilities to liquefaction when shaken by earthquakes,
together with explanation of the process and examples of its effects.
- A Southern california Earthquake Center (SCEC) collaborative study
to test and analyze different types of earthquake-rupture forecasts.
- Association of Bay Area Governments
offers shaking maps, liquefaction maps, predictive transportation
disruption maps, and more.
- In 1880 the California
Legistlature established the State Mining Bureau which has evolved during
its 127 years of continuous service into the modern California Geological
Central and Eastern US
- This map shows earthquakes (circles) greater than magnitude 3.0 since 1974
plotted on the 2014 USGS National
Seismic Hazard Map for the central and eastern United States. Warmer
colors on this map indicate areas of higher hazard. Larger earthquakes are
represented by larger circles. (PDF)
- Memphis, Shelby County, Tennessee, is located where damaging earthquakes
are only moderately likely, but the consequences of earthquakes, mainly
from the New Madrid seismic zone, can be very high. This densely populated
urban area is built on a 1-kilometer-thick sequence of sediments deposited
in a trough known as the Mississippi embayment. This thick pile of
sediments significantly affects earthquake ground motions. We, the
authors, have generated a suite of seismic hazard maps for a
six-quadrangle area in Memphis, Shelby County, Tennessee, that accounts
for these effects. These maps and their derivative products represent the
collaborative efforts of the U.S. Geological Survey (USGS) and its
- In tri-state Evansville area of Indiana, Kentucky, and Illinois the USGS
is partnering with a local working group to produce urban earthquake
hazard maps for the community.
- In the St. Louis area of Missouri and Illinois the USGS is partnering
with a local working group to produce urban earthquake hazard maps for the
- The USGS has produced a new series
of earthquake hazard maps for the City of Seattle. These “urban
seismic hazard” maps provide a much higher-resolution view of the
potential for strong earthquake shaking than previously available. This
new view is particularly important for Seattle, which sits atop a
sedimentary basin that strongly affects the patterns of earthquake ground
shaking and therefore, of potential damage.
- A Pacific Northwest Urban Corridor Geologic Mapping
Project of the Western Earth Surface Processes Team
- The urban corridor lies within the Puget-Willamtte lowland, a
seismically active forearc basin overlying the Cascadia subduction zone -
Pacific Northwest Urban Corridor Geologic Mapping Project of the Western
Earth Surface Processes Team